/**
 * IK 中文分词  版本 5.0
 * IK Analyzer release 5.0
 * 
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * 源代码由林良益(linliangyi2005@gmail.com)提供
 * 版权声明 2012，乌龙茶工作室
 * provided by Linliangyi and copyright 2012 by Oolong studio
 * 
 * 
 */
package org.wltea.analyzer.dic;

import org.apache.commons.lang3.concurrent.BasicThreadFactory;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.wltea.analyzer.cfg.Configuration;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 * 词典管理类,单子模式
 */

public class Dictionary {

	private final static Logger logger = LogManager.getLogger(Dictionary.class);

	private final static ScheduledExecutorService pool = new ScheduledThreadPoolExecutor(1,
			new BasicThreadFactory.Builder().namingPattern("sync-dic-schedule-pool-%d").daemon(true).build());

	/*
	 * 词典单子实例
	 */
	private static Dictionary singleton;
	
	/*
	 * 主词典对象
	 */
	private DictSegment _MainDict;
	
	/*
	 * 停止词词典 
	 */
	private DictSegment _StopWordDict;
	/*
	 * 量词词典
	 */
	private DictSegment _QuantifierDict;
	
	/**
	 * 配置对象
	 */
	private Configuration cfg;
	
	private Dictionary(Configuration cfg){
		this.cfg = cfg;
		Integer interval = cfg.getInterval();
		pool.scheduleAtFixedRate(new Monitor(), interval, interval, TimeUnit.SECONDS);

	}
	
	/**
	 * 词典初始化
	 * 由于IK Analyzer的词典采用Dictionary类的静态方法进行词典初始化
	 * 只有当Dictionary类被实际调用时，才会开始载入词典，
	 * 这将延长首次分词操作的时间
	 * 该方法提供了一个在应用加载阶段就初始化字典的手段
	 * @return Dictionary
	 */
	public static Dictionary initial(Configuration cfg){
		if(singleton == null){
			synchronized(Dictionary.class){
				if(singleton == null){
					singleton = new Dictionary(cfg);
					singleton.loadMainDict();
					singleton.loadStopWordDict();
					singleton.loadQuantifierDict();
					return singleton;
				}
			}
		}
		return singleton;
	}

	public static void sync (){
		singleton.loadMainDict();
		singleton.loadStopWordDict();
		singleton.loadQuantifierDict();
	}
	
	/**
	 * 获取词典单子实例
	 * @return Dictionary 单例对象
	 */
	public static Dictionary getSingleton(){
		if(singleton == null){
			throw new IllegalStateException("词典尚未初始化，请先调用initial方法");
		}
		return singleton;
	}
	
	/**
	 * 批量加载新词条
	 * @param words Collection<String>词条列表
	 */
	public void addWords(Collection<String> words){
		if(words != null){
			for(String word : words){
				if (word != null) {
					//批量加载词条到主内存词典中
					singleton._MainDict.fillSegment(word.trim().toLowerCase().toCharArray());
				}
			}
		}
	}
	
	/**
	 * 批量移除（屏蔽）词条
	 * @param words
	 */
	public void disableWords(Collection<String> words){
		if(words != null){
			for(String word : words){
				if (word != null) {
					//批量屏蔽词条
					singleton._MainDict.disableSegment(word.trim().toLowerCase().toCharArray());
				}
			}
		}
	}
	
	/**
	 * 检索匹配主词典
	 * @param charArray
	 * @return Hit 匹配结果描述
	 */
	public Hit matchInMainDict(char[] charArray){
		return singleton._MainDict.match(charArray);
	}
	
	/**
	 * 检索匹配主词典
	 * @param charArray
	 * @param begin
	 * @param length
	 * @return Hit 匹配结果描述
	 */
	public Hit matchInMainDict(char[] charArray , int begin, int length){
		return singleton._MainDict.match(charArray, begin, length);
	}
	
	/**
	 * 检索匹配量词词典
	 * @param charArray
	 * @param begin
	 * @param length
	 * @return Hit 匹配结果描述
	 */
	public Hit matchInQuantifierDict(char[] charArray , int begin, int length){
		return singleton._QuantifierDict.match(charArray, begin, length);
	}
	
	
	/**
	 * 从已匹配的Hit中直接取出DictSegment，继续向下匹配
	 * @param charArray
	 * @param currentIndex
	 * @param matchedHit
	 * @return Hit
	 */
	public Hit matchWithHit(char[] charArray , int currentIndex , Hit matchedHit){
		DictSegment ds = matchedHit.getMatchedDictSegment();
		return ds.match(charArray, currentIndex, 1 , matchedHit);
	}
	
	
	/**
	 * 判断是否是停止词
	 * @param charArray
	 * @param begin
	 * @param length
	 * @return boolean
	 */
	public boolean isStopWord(char[] charArray , int begin, int length){			
		return singleton._StopWordDict.match(charArray, begin, length).isMatch();
	}	
	
	/**
	 * 加载主词典及扩展词典
	 */
	private void loadMainDict(){
		//建立一个主词典实例
		_MainDict = new DictSegment((char)0);
		//读取主词典文件
        InputStream is = this.getClass().getClassLoader().getResourceAsStream(cfg.getMainDictionary());
        if(is == null){
        	throw new RuntimeException("Main Dictionary not found!!!");
        }
        
		try {
			BufferedReader br = new BufferedReader(new InputStreamReader(is , "UTF-8"), 512);
			String theWord = null;
			do {
				theWord = br.readLine();
				if (theWord != null && !"".equals(theWord.trim())) {
					_MainDict.fillSegment(theWord.trim().toLowerCase().toCharArray());
				}
			} while (theWord != null);
			
		} catch (IOException ioe) {
			System.err.println("Main Dictionary loading exception.");
			ioe.printStackTrace();
			
		}finally{
			try {
				if(is != null){
                    is.close();
                    is = null;
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		//加载扩展词典
		this.loadExtDict();
	}	
	
	/**
	 * 加载用户配置的扩展词典到主词库表
	 */
	private void loadExtDict(){

		boolean isMysql = true;
		logger.info("开始加载动态扩展词典");
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		try {
			Class.forName("com.mysql.jdbc.Driver");
			conn = cfg.getConnection();
			stmt = conn.createStatement();
			String extWordTable = cfg.getExtWordTable();
			String extWordField = cfg.getExtWordField();
			if(null != extWordTable && !"".endsWith(extWordTable) && null != extWordField && !"".equals(extWordField)){
				rs = stmt.executeQuery("select " + extWordField + " from " + extWordTable);
				while (rs.next()) {
					String theWord = rs.getString(extWordField);
					if (null != theWord && !"".equals(theWord)){
						_MainDict.fillSegment(theWord.trim().toCharArray());
					}
				}
			}else {
				logger.error("动态扩展词典配置不正确");
				isMysql = false;
			}
			logger.info("加载动态扩展词典成功");
		} catch (Exception e) {
			isMysql = false;
			logger.error("加载动态扩展词典失败",e);
		} finally {
			if (rs != null) {
				try {
					rs.close();
				} catch (SQLException e) {
				}
			}
			if (stmt != null) {
				try {
					stmt.close();
				} catch (SQLException e) {
				}
			}
			if (conn != null) {
				try {
					conn.close();
				} catch (SQLException e) {
				}
			}
		}

		if (!isMysql){
			logger.info("开始加载静态扩展词典");
			//加载扩展词典配置
			List<String> extDictFiles  = cfg.getExtDictionarys();
			if(extDictFiles != null){
				InputStream is = null;
				for(String extDictName : extDictFiles){
					//读取扩展词典文件
					System.out.println("加载扩展词典：" + extDictName);
					is = this.getClass().getClassLoader().getResourceAsStream(extDictName);
					//如果找不到扩展的字典，则忽略
					if(is == null){
						continue;
					}
					try {
						BufferedReader br = new BufferedReader(new InputStreamReader(is , "UTF-8"), 512);
						String theWord = null;
						do {
							theWord = br.readLine();
							if (theWord != null && !"".equals(theWord.trim())) {
								//加载扩展词典数据到主内存词典中
								//System.out.println(theWord);
								_MainDict.fillSegment(theWord.trim().toLowerCase().toCharArray());
							}
						} while (theWord != null);
						logger.info("加载静态扩展词典成功");
					} catch (IOException ioe) {
						System.err.println("Extension Dictionary loading exception.");
						ioe.printStackTrace();
						logger.error("加载静态扩展词典失败", ioe);
					}finally{
						try {
							if(is != null){
								is.close();
								is = null;
							}
						} catch (IOException e) {
							e.printStackTrace();
						}
					}
				}
			}

		}


	}
	
	/**
	 * 加载用户扩展的停止词词典
	 */
	private void loadStopWordDict(){

		//建立一个主词典实例
		_StopWordDict = new DictSegment((char)0);

		boolean isMysql = true;
		logger.info("开始加载动态停用词典");
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		try {
			Class.forName("com.mysql.jdbc.Driver");
			conn = cfg.getConnection();
			stmt = conn.createStatement();
			String extStopTable = cfg.getStopWordTable();
			String extStopField = cfg.getStopWordField();
			if(null != extStopTable && !"".endsWith(extStopTable) && null != extStopField && !"".equals(extStopField)){
				rs = stmt.executeQuery("select " + extStopField + " from " + extStopTable);
				while (rs.next()) {
					String theWord = rs.getString(extStopField);
					if (null != theWord && !"".equals(theWord)){
						_StopWordDict.fillSegment(theWord.trim().toCharArray());
					}
				}
			}else {
				logger.error("动态停用词典配置不正确");
				isMysql = false;
			}
			logger.info("加载动态停用词典成功");
		} catch (Exception e) {
			isMysql = false;
			logger.error("加载动态停用词典失败", e);
		} finally {
			if (rs != null) {
				try {
					rs.close();
				} catch (SQLException e) {
				}
			}
			if (stmt != null) {
				try {
					stmt.close();
				} catch (SQLException e) {
				}
			}
			if (conn != null) {
				try {
					conn.close();
				} catch (SQLException e) {
				}
			}
		}

		if (!isMysql){
			//加载扩展停止词典
			logger.info("开始加载静态停用词典");
			List<String> extStopWordDictFiles  = cfg.getExtStopWordDictionarys();
			if(extStopWordDictFiles != null){
				InputStream is = null;
				for(String extStopWordDictName : extStopWordDictFiles){
					System.out.println("加载扩展停止词典：" + extStopWordDictName);
					//读取扩展词典文件
					is = this.getClass().getClassLoader().getResourceAsStream(extStopWordDictName);
					//如果找不到扩展的字典，则忽略
					if(is == null){
						continue;
					}
					try {
						BufferedReader br = new BufferedReader(new InputStreamReader(is , "UTF-8"), 512);
						String theWord = null;
						do {
							theWord = br.readLine();
							if (theWord != null && !"".equals(theWord.trim())) {
								//System.out.println(theWord);
								//加载扩展停止词典数据到内存中
								_StopWordDict.fillSegment(theWord.trim().toLowerCase().toCharArray());
							}
						} while (theWord != null);
						logger.info("加载静态停用词典成功");
					} catch (IOException ioe) {
						System.err.println("Extension Stop word Dictionary loading exception.");
						ioe.printStackTrace();
						logger.info("加载静态停用词典失败", ioe);
					}finally{
						try {
							if(is != null){
								is.close();
								is = null;
							}
						} catch (IOException e) {
							e.printStackTrace();
						}
					}
				}
			}
		}



	}
	
	/**
	 * 加载量词词典
	 */
	private void loadQuantifierDict(){
		//建立一个量词典实例
		_QuantifierDict = new DictSegment((char)0);


		boolean isMysql = true;
		logger.info("开始加载动态量词词典");
		Connection conn = null;
		Statement stmt = null;
		ResultSet rs = null;
		try {
			Class.forName("com.mysql.jdbc.Driver");
			conn = cfg.getConnection();
			stmt = conn.createStatement();
			String extQuantifierWordTable = cfg.getQuantifierWordTable();
			String extQuantifierWordField = cfg.getQuantifierWordField();
			if(null != extQuantifierWordTable && !"".endsWith(extQuantifierWordTable) && null != extQuantifierWordField && !"".equals(extQuantifierWordField)){
				rs = stmt.executeQuery("select " + extQuantifierWordField + " from " + extQuantifierWordTable);
				while (rs.next()) {
					String theWord = rs.getString(extQuantifierWordField);
					if (null != theWord && !"".equals(theWord)){
						_QuantifierDict.fillSegment(theWord.trim().toCharArray());
					}
				}
			}else {
				logger.error("动态量词词典配置不正确");
				isMysql = false;
			}
			logger.info("加载动态量词词典成功");
		} catch (Exception e) {
			isMysql = false;
			logger.error("加载动态量词词典失败", e);
		} finally {
			if (rs != null) {
				try {
					rs.close();
				} catch (SQLException e) {
				}
			}
			if (stmt != null) {
				try {
					stmt.close();
				} catch (SQLException e) {
				}
			}
			if (conn != null) {
				try {
					conn.close();
				} catch (SQLException e) {
				}
			}
		}

		if (!isMysql){
			logger.info("开始加载静态量词词典");
			//读取量词词典文件
			InputStream is = this.getClass().getClassLoader().getResourceAsStream(cfg.getQuantifierDicionary());
			if(is == null){
				throw new RuntimeException("Quantifier Dictionary not found!!!");
			}
			try {
				BufferedReader br = new BufferedReader(new InputStreamReader(is , "UTF-8"), 512);
				String theWord = null;
				do {
					theWord = br.readLine();
					if (theWord != null && !"".equals(theWord.trim())) {
						_QuantifierDict.fillSegment(theWord.trim().toLowerCase().toCharArray());
					}
				} while (theWord != null);
				logger.info("加载静态量词词典成功");
			} catch (IOException ioe) {
				System.err.println("Quantifier Dictionary loading exception.");
				ioe.printStackTrace();
				logger.info("加载静态量词词典失败", ioe);
			}finally{
				try {
					if(is != null){
						is.close();
						is = null;
					}
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}

	}


	
}
